This invention relates to selective recycling operation for individual cylinders of an internal combustion engine having exhaust gas recycling and to an arrangement for practicing such single cylinder recycling operation.
To achieve increased richness of the exhaust gas in internal combustion engines, for example for desulfurization and/or regeneration of an Nox reservoir, it is known to return exhaust gas from a common exhaust line into a common intake duct supplying combustion gas to all of the cylinders of the engine. At least in the case of aspirating Diesel engines, it is also known that the exhaust gas return rate can be raised by throttling of the aspirated fresh air with a manifold throttle flap.
In addition, it is known that the intake to individual cylinders of an internal combustion engine may be throttled by arranging a tingle throttle flap in the individual intake line for the cylinder. With this arrangement, however, it is not possible to achieve a nearly oxygen-free exhaust gas flow.